<!doctype html>
<html lang="zh-CN">

<head>
	<meta charset="utf-8">
	<meta http-equiv="X-UA-Compatible" content="IE=edge">
	<meta name="viewport" content="width=device-width, initial-scale=1">
	<!-- 上述3个meta标签*必须*放在最前面，任何其他内容都*必须*跟随其后！ -->
	<title>贝塞尔曲线原理演示</title>

	<!-- Bootstrap -->
	<!-- <link rel="stylesheet" href="bootstrap.min.css"> -->

	<!-- HTML5 shim 和 Respond.js 是为了让 IE8 支持 HTML5 元素和媒体查询（media queries）功能 -->
	<!-- 警告：通过 file:// 协议（就是直接将 html 页面拖拽到浏览器中）访问页面时 Respond.js 不起作用 -->
	<!--[if lt IE 9]>
      <script src="https://cdn.jsdelivr.net/npm/html5shiv@3.7.3/dist/html5shiv.min.js"></script>
      <script src="https://cdn.jsdelivr.net/npm/respond.js@1.4.2/dest/respond.min.js"></script>
    <![endif]-->
	<style>
		#canvas {
			background: #eee;
			width: 600px;
			height: 400px;
			position: relative;
			margin: 50px auto;
		}

		#canvas>canvas {
			position: absolute;
		}
	</style>
</head>

<body>
	<div id="canvas">
		<canvas id="bg" width="600" height="400"></canvas>
		<canvas id="lines" width="600" height="400"></canvas>
		<canvas id="curve" width="600" height="400"></canvas>
	</div>
</body>

</html>